Drilling bit



Aug. 17, 1937. c. H. MANGELS DRILLING BIT Filed Nov. 11, 1935 INVENTOR more: A! fix/mas.

6.4 BY W ATTORNEY Patented Aug. 17, 1937 acetate mirth srarss ria'reur or ies DRILLING BIT Clarence H. Mangels, Long Beach, Calif.

Application November 11, 1935, Serial No. 49,200

4 Claims.

This invention relates to a drilling bit particularly applicable for deep bores, such as oil wells, and is preferably of the drag type.

An object of my invention is to provide a bit having a novel detachable cutter head and a novel means of holding the head securely in position on the bit shank.

Another object is to provide novel circulation holes in the bit body and cutter head, these circulation holes being so arranged that the cutters will be effectively washed, and the cut material effectively removed from the bit.

Other objects, advantages and features of invention may appear from the accompanying drawing, the subjoined detailed description and the appended claims.

In the drawing Figure 1 is a side elevation of my bit.

Figure 2 is a top plan view of the cutter head.

Figure 3 is a side elevation of the same.

Figure 4 is a bottom plan view of the same.

Figure 5 is a bottom plan view of the bit body.

Figure 6 is a fragmentary sectional view taken on line E6 of Fig. 1.

Referring more particularly to the drawing, the numeral 4 indicates the bit shank or body, on the upper end of which I provide a suitable coupling means, such as the threaded pin 2.

A cutter head 3 is removably mounted on the 30 lower end of the shank i and comprises a body portion 1 from which a plurality of cutter blades depend. These cutter blades include a plurality of outer or reaming cutters 5. There are preferably six of these cutters, three on each side of the transverse center line of the bit. These cutters are integrally formed with the body 4. The cutting edges of each of the cut ers are preferably on a radial line from the center of the bit. A pair of core breaking cutters E are provided at the center of the bit body; and between the outer cutters 5 and the core breaking out ters 5, I have arranged a pair of intermediate cutters l, 8. The cutting edges of these last named cutters are preferably slightly in advance of the radial line from the center of the bit. The purpose of these last named cutters is to remove the material which is not cut by the cutters 5 or 6. All of the cutters 5, i, and 3 are integrally formed with the body 4 and are of varying lengths, i. e., the outer cutters 5 are the longest, the trimming cutters 5 are the shortest, and the cutters 'i, 8 are of intermediate length.

The cutter body 3 is removably mounted on the shank l in the following manner-a pair of arcuate grooves 9, It are formed in the bottom of the shank i. These grooves are eccentric to the center of the shank so that the cutter head will more effectively look when placed on the shaft. The cutter head 3 is provided with a pair of arcuate lugs ii, 52 on the top 5 thereof which fit into the grooves 9, iii, respectively. The grooves 3, it and the lugs ii, i2. are tapered from one end to the other in addition to being arcuate. It will be evident that the cutter head is mounted on the bit shank by a partial right hand rotation, thereby fitting the lugs H, i2 in the grooves 9, i i, respectively.

A set screw it extends thru the shank and bears against the lugs it or E2, thereby preventing retraction of the bit body.

A pair of shoulders it, it are provided on the outer periphery of the shank and the cutter head is formed with upstanding lugs it, ii which engage the shoulders it, it, respectively, thereby preventing the cutter head from moving too far in a clockwise direction.

The shank i is provided with a fluid bore it which extends to a pair of elongated ports is, 2t. The cutter head is provided with a pair of ports 2 i, 22, which coincide with the ports it, it, respectively. Thus, drilling fluid is emitted from the bottom or the bit and immediately in front of the cutters i, 8. As the fluid passes out of the ports 2 i, 22, it will wash over the cutters i, 8 and then pass outwardly to wash over the outer cutters 5. Thus, the circulating fluid will eiiectively cleanse the cutters of detritus.

Having described my invention, I claim:

1. A drilling bit comprising a shank, said shank having a pair of arcuate and tapered grooves in the bottom thereof, a cutter head, a pair of arcuate tapered lugs on the cutter head extending into said grooves, stop shoulders on the shank, stop lugs on the cutter head engaging said shoulders, a set screw extending thru the shank and engaging the cutter head whereby said head is held against retraction, and a plurality of cutters depending from the cutter head.

2. A drilling bit comprising a shank, said shank having a pair of arcuate and tapered grooves in he bottom thereof, a cutter head, a pair of arcuate tapered lugs on the cutter head extending into said grooves, stop shoulders on the shank, stop lugs on the cutter head engaging said shoulders, a set screw extending thru the shank and engaging the cutter head whereby said head is held against retraction, a. plurality of cutters depending from the cutter head, a longitudinal fluid bore in the shank, a pair of eccentrioally positioned ports in the bottom of the shank, said ports connecting with said bore, said cutter head having a pair of outlet ports therein, said last named ports, coinciding with the ports in the shank.

3. A drilling bit comprising a shank, said shank having a pair of arcuate and tapered grooves in the bottom thereof, a cutter head, a pair of arcuate tapered lugs on the cutter head extended into said grooves, a set screw extending through the shank and engaging the cutter head whereby said head is held against retraction and a plurality of cutters depending from the cutter head.

4. A drilling bit comprising a shank, said shank having a pair of arcuate and tapered grooves in the bottom thereof, a cutter head, a pair of arcuate tapered lugs on the cutter head extended into said grooves, a set screw extending through the shank and engaging the cutter head whereby said head is held against retraction and a plurality of cutters depending from the cutter head, a longitudinal fluid bore in the shank, a pair of eccentrically positioned ports in the bottom of the shank, said ports connecting with said bore,

said cutter headhaving a. pair of outlet ports 11 therein, said last named ports coinciding With the ports in the shank.

CLARENCE H. MANGELS. 

